Added some plugin options to schema to allow for later changes

Added the saltlen, iterations, keylen, and encoding options directly
onto the schema options to allow a developer to update a users
salt/key/iterations value after the user has already created a
password. The developer can check the document version and if its an
old version, authentic using the old salt/keylen/iterations/encode and
once authenticated, then switch to the new values and set the password
and update the document version number. All tests passing.